|
Common Stock (Details) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | 81 Months Ended | |
|---|---|---|---|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
Mar. 31, 2013
|
|
| Components of stock-based compensation | |||
| Total stock-based compensation expense | $ 1,523 | $ 874 | $ 9,035 |
|
Employee awards [Member]
|
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| Components of stock-based compensation | |||
| Total stock-based compensation expense | 972 | 313 | 4,178 |
|
Non-employee awards [Member]
|
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| Components of stock-based compensation | |||
| Total stock-based compensation expense | 434 | 445 | 3,847 |
|
Non-employee warrants [Member]
|
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| Components of stock-based compensation | |||
| Total stock-based compensation expense | $ 117 | $ 116 | $ 1,010 |